Winds Drive Canadian Wildfire Smoke Into US, Triggering Air Quality Concerns Across Midwest

The Minnesota Pollution Control Agency warned on Friday that fine particle levels are expected to be unsafe in northern Minnesota.
Winds Drive Canadian Wildfire Smoke Into US, Triggering Air Quality Concerns Across Midwest
Wildfires in Flin Flon, Manitoba, Canada, on May 27, 2025. Manitoba government via AP
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Smoke from dozens of wildfires burning in Canada drifted south into the United States on Friday, carried by powerful upper-level winds and prompting air quality warnings across several Midwestern states, according to the U.S. Environmental Protection Agency.

The influx of smoke created unhealthy conditions for people and animals sensitive to pollution in parts of Minnesota and Wisconsin, with the agency’s AirNow interactive map showing a prominent strip of orange—indicating elevated pollution—moving from northwest to southeast across Wisconsin as of Friday afternoon.

Most of the state, along with Michigan’s Upper Peninsula, eastern Iowa, and northwestern Illinois, registered moderate air quality.

The Minnesota Pollution Control Agency warned in a Friday post on X that fine particle levels are expected to reach the red AQI level in northern Minnesota, which is unsafe for everyone.
To reduce exposure to unhealthy air, health officials recommend staying indoors with windows and doors closed, avoiding heavy exertion outdoors, and not using fans or swamp coolers that draw in outside air. Residents are also urged to avoid using wood-burning appliances, candles, and incense, the Minnesota Pollution Control Agency said in a May 30 press release.

Smoke’s Reach, Future Path

Patrick Ayd, a meteorologist with the National Weather Service in Duluth, Minnesota, said the smoke consists of particulates from burning trees, leaves, and other vegetation.

“Over the next day or so, particulates from the burning trees, leaves, and other vegetation could reach further south into Oklahoma, Tennessee, and Arkansas,” Ayd said.

Local residents are already feeling the effects. Murray Kinsey, who owns a houseboat company just outside of Babbitt, Minnesota, said Friday afternoon that the sky was “hazy,” but fishing continued on nearby Birch Lake.

“It’s getting a little hard to breathe,” Kinsey said. “But it’s not terrible. We’ve had it before, but it’s been way worse.”

Air Quality Index

The Air Quality Index, or AQI, is the standard tool for measuring how clean or polluted the air is on any given day, according to AirNow. The AQI evaluates the impact of ground-level ozone, particle pollution (particulate matter), carbon monoxide, sulfur dioxide, and nitrogen dioxide. Of these, ground-level ozone and airborne particles are considered the most significant threats to human health in the United States.

The AQI scale ranges from green, representing satisfactory air quality with little or no risk, to maroon, which signals hazardous conditions and health warnings of emergency situations for the entire population.

On Friday morning, the AQI showed orange in the Arrowhead region of Minnesota, which Ayd described as a concern for people with chronic health conditions, the elderly, and young children. “They really should limit their time outdoors,” Ayd said. The orange zone continued to move south and southeast throughout the afternoon.

The level below orange is yellow, which is considered moderate and acceptable for most people. This was the status for other parts of the Midwest as shown on the AirNow map on Friday.

Meteorological Factors, Outlook

The smoke’s journey south is being driven by winds high in the atmosphere.

“We are getting the smoke,” said Kevin Doom, a meteorologist with the National Weather Service in Chicago. “The winds way up in the atmosphere—10,000, 20,000 feet up—are blowing in from the north today. Minnesota is kind of taking the brunt at the moment.”

Doom added, “The wind is going to drag that smoke down over the next day or two.”

He noted that a little haze was visible over Chicago on Friday morning. “It will keep moving with the wind,” he said. “But over time, it will continue to disperse, mix in with the air until it gets thinner and thinner until it fades away.”

Meteorologist Zachary Yack with the National Weather Service said, “It looks like the smoke is moving in behind the cold front.” He added, “Most of the smoke is thinning behind the front.”

The source of the smoke is nearly two dozen wildfires burning in Manitoba, just north of Minnesota and North Dakota. The province has seen more than 100 wildfires so far this year. On Wednesday, Manitoba officials declared a state of emergency as fires forced 17,000 people to evacuate their homes in several communities.

Canada’s wildfire season runs from May through September, with 2023 marking its worst wildfire season on record. That year, smoke from Canadian fires blanketed much of North America for months.

Past wildfire seasons have also affected U.S. air quality. Last summer, fires in California, Oregon, Arizona, Washington, and Canada filled skies with smoke and haze, leading to air quality alerts in many areas.

The Associated Press contributed to this report.